final exam Flashcards
what is the lung root?
attaches pleural cavities to mediastinum
why does each lung have its own cavity?
to prevent the spread of infection if one gets infected
why is the L lung smaller than the right?
the heart is positioned slightly to the L
how many lobes do each lung have?
R- 3, superior, middle, inferior
L- 2, inferior and superior
what is the pulmonary network and bronchial arteries?
p- carries blood to lungs to get O
b- provides blood to lung tissue
what is the visceral and parietal pleura?
v- in contact w lungs
p- covers thorasic wall
what lubricates the space between the lungs
pleural fluid, to reduce friction
what is lung compliance
lung stretch.
determined by distensibility (ablility to expand) of lung tissue and thorasic cage and alveolar surface tension
what does a decrease in lung resilience do to compliance?
reduces compliance, isnt able to return to original shape after stretching
what reduces surface tension in lungs?
surfactant, produced by type 2 alveolar and makes it easier to breathe
what is tidal volume
the amount of air that moves in and out of the lungs with each breath during quiet breathing (normal breathing).
It averages 500 mL per breath
what is inspiratory reserve volume
the amount of air that can be inspired beyond (forced) the tidal volume.
what is expiratory reserve volume
the amount of air that can be forcibly expired from the lungs
after tidal expiration.
what is vital capacity
the sum of tidal volume, inspiratory reserve, and expiratory reserve volumes and is the total amount of exchangeable air.
the most air you have
what is residual volume
volume of air remaining after max foreced expiration, air that doesnt leave your lungs
what is total lung capasity
sum of all lung volumes
what is boyles law?
states that pressure changes lead to gas flow.
explains the motion of air in and out of our lungs
if air pressure in lungs is higher what will happen?
air will move out of lungs
if air pressure is lower inside lungs what will happen?
air will be drawn in
what happens in quite insiration?
the diaphragm and intercostal muscles contract, increasing the thoracic volume. Intrapulmonary pressure to drop below atmospheric pressure, and air flows into the lungs
what happens during forced inspiration?
accessory muscles of the neck and thorax contract, further increasing thoracic volume.
what does alveolar surface tension do?
draws walls of alveoli together making a force that must be over come to expand the lungs
what is quite expiration
normal exhale, causes thorasic muscs to relax
what is forced expiration?
abdominal muscs contract increasing intraabdominal pressure and forces air out
what are nonrespiratory air movements
cause movement of air in and out of lungs but unrelated to breathing
this is like coughing or sneezing
what is intrapulmonary pressure
pressure in alveoli
what is intrapleural pressure
pressure in pleural cavity
what is transplumonary pressure
the difference between intrapulmonary and intrapleural pressure: the greater the transpulmonary pressure, the larger the lung volume.
what is airway resistance
the change in transpulmonary pressure needed to produce a unit flow of gas through the airways of the lung.
what physical factors influence pulmonary ventilation?
airway resistance
alveolar surface tension
lung compliance
what is pulmonary ventillation
breathing
the air moving in and out of lungs
explain what happens when you inhale
diaphragm contracts to fill lungs as it pulls down thorasic cavity making air in lungs at a lower pressure than the outside which draws in more air
explain what happens when you exhale
the diaphragm relaxes, acessory muscs around neck and shoulder contract, and volume of the thoracic cavity decreases, while the pressure within it increases. As a result, the lungs contract and air is forced out
what is daltons law of partial pressures?
states that the total pressure exerted by a mixture of gases is the sum of the partial pressures exerted by each gas in the mixture
sees what things in the mixture contributes whta to the air
Describe how atmospheric and alveolar air differ in composition, and explain these differences.
less O and more CO2 in alveolar air than outside because you actively make CO2 and use O
what is total atmospheric pressure
pressure outside of the body
760mmHG
what is partial pressure
the pressure from a specific gas in the air ex notrogen makes up 78.6% of air
if nitrogen makes up 78.6% of the air what is the partial pressure?
.786 x 760 mm Hg = 597mm Hg
what is henrys law
states that when a mixture of gases is in contact with a liquid, each gas will dissolve in the liquid in proportion to its partial pressure
Relate Dalton’s and Henry’s laws to events of external and internal respiration.
what is ventilation perfusion coupling
the matching of alveolar ventilation with pulmonary blood circulation
automatic sys that pairs how much breathing ur doing w how much blood is flowing thru ur tissues
what controls perfusion
P o2 by changing arteriolar diameter
what controls ventilation
P co2 by changing bronchiolar diameter
Describe how oxygen is transported in blood.
up to 4 O molecules can bound to a hemoglobin molecule. it binds to the iron in the centre of the hemoglobin.
hemoglobin picks up O and drops it off in tissues when they need it like during exercise, warmer temps and when you have more CO2
what is hypoxia?
inadequate O2 delivery to tissues
is plasma partial pressure of O rises what happens to hemoglobin? what abt if it falls?
rise- hemoglobin unloads little O
lowers- more O unloaded
anemic hypoxia
ischemic hypoxia
a- too few RBC or too little hemoglobin
i- blocked circulation
histotoxic hypoxia
hypoxemic hypoxia
hi- cells unable to use O, when theres a poison that prevents them
hy- insufficient O
what is carbon monoxide poisoning? (hypoxia)
typically from fire, hemoglobin has 200x greater affinity for carbon monoxide than for O, therefore wants to stick to it more than O
what is carbonic acid–bicarbonate buffer system
formed when CO2 combines with water and dissociates, producing carbonic acid and bicarbonate ions that can release or absorb H to keep pH stable
Describe how carbon dioxide is transported in the blood.
transported in 3 ways;
-7-10% dissolved in plasma
-20% carried on hemoglobin
-70% exists as bicarbonate ions
what does slow shallow breathing do
increases CO2 in blood causing a drop in pH
what are the neural controls of respiration?
ventral respiratory group and dorsal respiratory
both located in the medulla oblongata
what is the ventral respiratory group?
generates baseline rhythm of inhalation and exhalation.
has neurons that control the contration of diaphragm and external intercostal muscles during resporation
what is the dorsal respiratory group?
receives sensory input from peripheral stretch and chemoreceptors and communicates w ventral group
what is the pontine respiratory group?
within the pons,
modifies breathing rhythm to smooth out transitions between inspiration and expiration.
how does arterial pH affect breathing?
decreased pH increases breathing rate bc breathing faster and deeper increases the amount of carbon dioxide exhaled, which raises the blood pH back toward normal.
what factors influence breathing
pH and changing levels of O and CO2
what are peripheral chemoreceptors?
in aortic arch and carotid arteries.
theyre sensitive to arterial P o2 and monitor arterial BP
can detect a change in arterial pH which causes breathing rate to change
what is hyperventilation?
unnecessary heavy breathing,
leads to decreased blood CO2 which causes vasoconstriction and ischemia which can lead to dizzy and fainting
what is hyperpnea?
high breathing rate for a specific reason, like exercise
Pulmonary irritant reflexes
respond to inhaled irritants by causing reflexive broncoconstriction in airways
inflation or Hering-Breuer reflex
activated by stretch receptors in visceral pleurae and airways, this protects the lungs from over expanding by inhibiting inspiration
Describe the process and effects of acclimatization to high altitude
after long term change from sea level to high altitudes it results in acclimation of the body,
there is less O and thinner air which causes you to take more breaths and make more RBC
this increases ventilation rate, lower hemoglobin saturation, and increased production of erythroprotein
what is acute mountain sickness (AMS)?
acute mountain sickness (AMS),
may result from a rapid transition from sea level to altitudes above 8000 ft bc atmospheric pressure and P o2 levels are lower at high elevations
what are obstructive pulmonary diseases?
hyperinflation of lungs,
problem within trachea, larynx or bronchi making it harder to get air in and out and causes ppl w this to have bigger lungs that are over inflated, higher vital capacity
what is restrictive pulmonary diseases?
a disease that causes damage to elastic tissue so lung doesn’t expand well, causes smaller lungs, low vital capacity
what is emphysema?
permanently enlarged alveoli and deterioration of alveolar walls, causes more effort to breathe
what is bronchitis?
inhaled irritants result in inflammation of bronchi, excessive mucous production as well as fibrosis
impairs lung ventilation and gas exchange
what is asthma?
inflamed airways caused by a combo of genetics and environmental factors.
causes airways to thicken.
caused by release of interleukins and mucous
what are the 4 main functions of the dig sys?
take in food
break it down into nutrient molecules
absorb nutrient molecules into blood stream
rid body of any indigestible remains
what is the alimentary canal?
tube from mouth - anus
order: mouth, pharynx, esophagus, stomach, SI, LI
what are the 4 layers of the alimentary canal starting deepest?
mucosal layer
submucosa
musularis
serosa
what is the mucosa and submucosa layers?
m- inner most, moister, lines entire dig tract, provides secretions to GI lumen, absorbs, and protects against infectious disease
s- dense CT containing blood ves and lymph ves, and nerves
what are the muscularis and serosal layers?
m- smooth musc that preforms peristalsis and segmentation, stomach has 3 layers and everywhere else has 2
s- protective outer layer, forms visceral peritoneum, attaches canal to tissues or mems
what are the first 3 steps of processing food?
- ingestion, in mouth, takes food to GI tract.
- in mouth, secretion of dig enzymes.
- motility, mechanical breakdown and moving things along thru peristalsis and segmentation
what is peristalsis?
squeezing behind the food in order to move forwards
what is segmentation?
contracts and relaxes back and forth to churn, break down, and mix food
what are the last 3 steps in food processing?
- digestion, chem breakdown.
- absorption, in SI, movement of digested products from lumen to blood or lymph
- defecation, eliminates waste thru anus
what is splanchnic circulation?
the supply of blood that goes to the GI tract.
incudes arteries that branch off abdominal aorta to dig organs
what is the hepatic portal sys?
sends blood from GI tract to liver to finish filtering and breaking down toxins to prevent them from joining circulation
wht is visceral and parietal peritoneum?
v- covers organs
p- lines body wall of abdom cav
what is the peritoneal cavity
between vis and parietal peritoneum and its filled w serous fluid to prevent friction while organs moves
what is retroperitoneal? what organs are included in this?
organs that are found posterior to the mesentery lying against dorsal wall. ( not in abdom cav technically)
organs; pancreas, duodenum, and parts of LI
what are messenteries?
double layer of peritoneum that allows vessels and nerves to reach dig organs and holds the organs in place, also stores fats
what are the greater and lesser omentums?
g- hangs from inferior/greater curve of stomach infront of intestines
l- hangs from liver to superior/lesser curve of stomach
what is the enteric nervous sys
GI tracts own nerv sys.
made up of myenteric plexus and submucosal plexus.
controls long and short reflexes.
measures how muc food youre eating in order to regulate how much acids should be made
myenteric plexus
within muscular layer, it coordinates segmentation and peristalsis in the intestines
submucosal plexus
controls local muscle, intestinal secretion, local absorption, and local contraction and regulates forwards movement of dig
what are short and long reflexes?
s- mediated by enteric neurons, reflex in GI tract
l- also involves CNS and extrinsic nerves, goes to brain then back down
what 3 components determine regulation of digestion
-variety of chem and mech stimuli to promote dig activity
-smooth musc and glands are the effectors in GI tract
-neurons and hormones control dig activity
what is the mucosal layer of the mouth?
stratified squamous
what is the palate? what are its two parts?
roof of the mouth.
hard palate- bony, aids in manipulation of food.
soft palate- rises during swallowing to close the nasopharynx
what is the purpose of the skeletal muscle that covers lips and cheeks?
helps to keep food between the teeth while chewing
what is the tongue?
made of skeletal musc
used to reposition food in chewing, mix food w saliva, initiate swallowing, and helps w speech.
you have voluntary control of it
what and how is saliva produced?
saliva is mainly water w electrolytes and enzyme called amylase, ligual lipase, antibodies, and metabolic wastes.
composed of serous cells, that produce a watery secretion, and muscus cells, that produce mucus.
what do lingual lipase and salivary amylase break down?
l- lipids
a- starch
how saliva do you produce on av a day?
1L- 1.5L
what are the 3 salivary glands?
-sublingual gland, under tongue
-submandibular gland, jaw area
-parotid duct, by ear or cheeks
what is the function of saliva?
begins chemical dig,
breaks down carbs,
moistens food.
what begins mech dig?
teeth, using mastication (chewing)
what is precise dentition? what has it?
top and bottom teeth fit w each other,
only mammals have this
what are primary dentition or deciduous teeth?
baby teeth
20 in total
teeth that are lost to make room for permanent teeth
what are permanent dentition?
permanent/adult teeth
32 in total
what are the types of teeth? what are they for?
incisors, cutting
canines, tering
premolars, crushing
molars, grinding
what is the adult human dental formula?
I 2/2
C 1/1
P2/2
M 3/3
explain the dental formula
the top # is top teeth,
bottom # is bottom teeth,
only accounts for half of the mouth and assumes both sidea are equal because humans are symentrical
what is the crown?
hardest part of tooth,
covered w enamel,
exposed part of tooth
what is the root of the tooth?
the part embedded in the gums
why do you get two sets of teeth?
because the head and jaw grows so you need more teeth
what is cementum? dentin? pulp cavity?
c- calcified CT that anchors root into periodontal ligaments
d- bone like material under enamel and surrounds pulp cav
p- provides supply of blood and nerves
what are 2 ways you can get cavities?
sugars- the bacteria in mouth breakdown sugar and produce acid, too much consumption of sugar and production of acid breaks down teeth causing demineralization and cavities.
gum erosion- the neck of tooth becomes exposed and it is not covered w enamel leading to cavities
what is function of the pharynx
musc contractions within the walls propels food to esophagus
what is the function of the esophagus
passageway for food and fluids from laryngopharynx to stomach at the cardial orifice.
when does heartburn occur?
when the gastroesophageal (cardiac) sphincter isnt able to stay closed when moving stuff from esoph to stomach and the acid gets out
describe the mechanism of swallowing
buccal phase- voluntary, occurs in mouth where bolus is forced into oropharynx by tongue.
pharyngeal-esophageal phase- involuntary, occurs when food is squeezed thru the phaynx and into esoph. controlled by the medulla and pons.
what are 7 functions of the stomach?
1 mech and chem break down.
2 holding area for food.
3 delivers chyme to SI.
4 denatures pros w hydrochloric acid.
5 pepsin carries out enzyme dig of pros.
6 absorbs alc and asprin into blood thru endothelium.
7 secretion of intrinsic factor for B12 absorption.
what is the cardia and pyloric area in the stomach?
c- where food enters
p- controls movement of food out of the stomach
what is the mucosa of the stomach?
simple columnar w goblet cells that provide protective cover of alkaline mucus
what are the purpose of gastric glands of the stomach?
produce gastric juice that denatures pros and lipids.
mix of mucus, acid, enzymes, hormones, and intrinsic factor
what are surface mucous cells, mucous neck cells, and parietal cells of the stomach?
m- secretes mucous, keeps acid at bay.
mnc- secretes diff type of mucus.
p- makes hydrochloric acid and intrinsic factor to absorb B12 ans denature pros.
what are chief and enteroendocrine cells of the stomach?
c-secretes pepsinogen and gastric lipase to breakdown pros.
e- secretes hormones for communication between dig organs and coordinates activity.
Explain how gastric secretion and stomach motility are regulated.
by neutral and hormonal mechanisms that stimulate or inhibit the enteric neurons of the gut, which are organized as ganglionated plexuses and innervate the smooth muscles of the GI tract.
what is gastrin and somatostatin?
g- produced by G cells in stomach, stimulate gastric secretions and promote movement of food thru tract. ( activates dig sys)
s- from the stomach muscosa and duodenum, inhibits dig acvitity
what is histamine and serotonin in the stomach?
h- increases stomach acid (HCI)
s- regulate and stimulate musc contraction
what is gherlin?
hunger hormone.
released by stomach mucosa to stimulate hunger
how are gastric secretions regulated/what are the phases?
cephalic phase- before food enters, reflex trigger by sight ot thought of food.
gastric phase- lasts 3-4- hrs, triggered by stretch when foods in stomach, releases gastric juices and churns food.
intestinal phase- slow gradual release of chyme into SI
how do parietal cells make hydrochloric acid?
by pumping acidic ions one way and bicarbonates the other way. acid ions to stomach and basic to blood.
what is alkaline tide?
the balancing of acids and bases in stomach and blood. puts acids in stomach and bases in blood.
how is gastric motility regulated?
controlled by contractility of smooth muscles of the GI tract, extrinsic and intrinsic neurons (motor and sensory) and neural hormonal mechinisms